Ignition system



May 29, 1956 B. H. SHORT 2,748,319

- IGNITION SYSTEM Filed March 20, 1951 INVENTOR. k g g BY MW IGNITION SYSTEM Brooks H. Short, Anderson, Ind, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Application March 20, 1951, Serial No. 216,641

3 Claims. (Cl. 315--213) This invention relates to ignition apparatus for automotive vehicle engines and its object is to increase the heat of spark by increasing the duration of sparking initiated by the discharge of a condenser which is charged between firing intervals and is caused to discharge by an engine driven timing apparatus.

To accomplish this object, the disclosed embodiment of the present invention includes a source of relatively high voltage, a main condenser charged thereby, a distributor having posts and an engine driven rotor carrying a contact which is connected with the main condenser and which closely approaches the posts in succession, ignition coils each connected with a post and having a primary winding through which the main condenser discharges when the rotor contact is in close proximity to the post connected with the primary winding, each coil having a secondary winding connected with an engine spark plug, and an auxiliary condenser which is charged by the source and which is connected in series with each secondary winding and spark plug, the auxiliary condenser discharging across the spark plug gaps in succession when they fire.

Further objects and advantages of the present invention will be apparent from the following description, reference being bad to the accompanying drawing wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

The drawing is a wiring diagram of an ignition system embodying the present invention.

Referring to the drawing, a battery 10 is connected by switch 11 with a field winding 12 of an A. C. generator 13. Winding 12 is connected with the grounded terminal of the battery by a resistance 14 or by a switch 15 which can be closed to by-pass the resistance. At low engine speeds, switch 15 is closed in order to obtain greater field excitation; and, at higher engine speeds, switch 15 is opened. The terminals of generator 13 are connected with a rectifier 16 which places a relatively high D. C. potential on a terminal 17 connected with a main condenser 18. During the intervals between ignition impulses, the condenser 18 is charged by the potential provided by the generator 13 and rectifier 16.

Terminal 17 is connected with the engine driven rotary contact 19 of a distributor 20 which provides a plurality of posts 21 past which the rotor 19 moves in succession. Each post 21 is connected with a primary winding 2.2 of an ignition coil 23 having a secondary winding 24 connected with a spark plug 25. Each secondary winding 24 is connected with a wire 26 connected with an auxiliary condenser 27 which is connected by a charge rate controlling resistance 28 with terminal 17.

When the rotor 19 approaches closely to a distributor post 21, the main condenser 18 discharges through the primary winding connected with that post. There is induced in the associated secondary winding 24, a voltage sufficient to cause break down of the gap at the spark plug 25 connected therewith. The break down across the gap of the spark plug 25 provides a path for discharge of the auxiliary condenser 27 which functions to prolong the duration of discharge at the spark plug gap whereby the heat of spark is substantially increased.

The auxiliary condenser 27 serves all of the spark plugs in this manner in succession.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be un derstood that other forms might be adopted.

What is claimed is as follows:

1. An ignition system for automotive vehicle engines comprising a constant source of relatively high D. C. voltage, a main condenser charged thereby, a distributor having posts and an engine driven rotor carrying a contact which is connected to the source and which closely approaches the posts in succession, ignition coils each connected with a post and having a primary winding through which the main condenser discharges progressively when the rotor contact is in close proximity to the post connected with the primary winding of each of said coils, each coil having a secondary winding connected with an engine spark plug, and an auxiliary condenser which is charged by and connected to the source through a resistor and which is also connected in series with all of said secondary windings and spark plugs, the auxiliary condenser discharging across the spark plug gaps in succession when they fire.

2. In an ignition system, an alternating current generator; a rectifier in circuit therewith for producing a single constant source of direct current; a condenser connected to the output of said rectifier; an ignition distributor having a plurality of contacting positions in parallel circuit with said condenser; a plurality of ignition coils, each having a primary and a secondary; one side of the primary winding of each coil being connected to one position of said distributor; a plurality of spark plugs, one of which is connected to one side of each of said ignition coil secondary; and a single auxiliary condenser connected in series with theother side of all of said secondaries and also connected with the output of said rectifier through a resistor, whereby said distributor when actuated connects singly and progressively the pri maries of said ignition coils with said output, for causing a predetermined sequence of discharge in said plugs.

3. In an ignition system for an internal combustion engine having a source of direct current, a main condenser charged thereby, a plurality of ignition coils hav ing primary and secondary windings, and a plurality of spark plugs connected with said secondary windin improvement which comprises; a distributor h' plurality of stationary contacts, each of which is connected to one of the primary windings, and an engine driven rotor carrying a movable contact operable to complete a circuit with each of said stationary contacts for sequentially discharging said main condenser through said primary windings to initiate sequential sparking of the plugs; and an auxiliary condenser charged by the source through a resistor and connected in series with all of said secondary windings and said spark plugs for increasing the duration of sparking of each plug.

References Cited in the file of this patent UNITED STATES PATENTS 791,856 Apple June 6, 1905 955,618 Varley Apr. 19, 1910 995,489 Silva June 20, 1911 2,180,358 Hooven Nov. 21, 1939 2,184,315 Peters Dec. 26, 1939 2.219,317 Holliday et a1 Oct. 29, 1940 2,459,297 Smith Jan. 18, 1949 2,497,307 Lang Feb. 14, 1950 2,503,054 Laird Apr. 4, 1950 2,536,143 Short Jan. 2, 1951 2,540,177 Short Feb. 6, 1951 2,616,065 Short Oct. 28, 1952 

